Summary of findings 4. Preparation/information compared to control for needle‐related procedural pain and distress in children and adolescents.

Preparation/information compared to control for needle‐related procedural pain and distress in children and adolescents
Patient or population: children aged 3‐12 years with mixed medical (acute or chronic illness) or unclear diagnoses undergoing venipuncture or intravenous insertion Setting: hospital (outpatient/emergency department) or community clinic Intervention: preparation/information Comparison: control
Outcomes	Anticipated absolute effects* (95% CI)		№ of participants (studies)	Certainty of the evidence (GRADE)	Comments**
	Risk with control	Risk with preparation/information
Self‐reported pain	The mean level of self‐reported pain in the control group ranged from 2.6 to 6.12 (adjusted to a 0 to 10 scale)	The mean level of self‐reported pain with preparation/information was 0.18 standard deviations lower (0.60 lower to 0.23 higher)	313 (4 RCTs)	⊕⊝⊝⊝ VERY LOW a,b,c	There is no evidence of an effect of preparation/information
Self‐reported distress	See comment	See comment	See comment	‐	This outcome was not assessed in any study
Observer‐reported pain	See comment	The mean level of observer‐reported pain with preparation/information was 0.40 standard deviations lower (0.98 lower to 0.18 higher)	259 (3 RCTs)	⊕⊝⊝⊝ VERY LOW a,b,c	There is no evidence of an effect of preparation/information
Observer‐reported distress	See comment	See comment	100 (1 RCT)	‐	This outcome was assessed in one study only
Behavioral measures‐ pain	See comment	See comment	39 (1 RCT)	‐	This outcome was assessed in one study only
Behavioral measures‐ distress	See comment	See comment	54 (1 RCT)	‐	This outcome was assessed in one study only
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). **One 'rule of thumb' for interpreting the relative effect is that 0.2 represents a small difference, 0.5 a moderate difference and 0.8 a large difference. CI: Confidence interval; SMD: standardized mean difference; RCT: randomized controlled trial
GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of the effect Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect

^a Downgraded once for serious study limitations: most trials had unclear/high risk of bias in blinding, allocation concealment and/or selective reporting of outcomes.
^b Downgraded once for inconsistency due to moderate heterogeneity (I²) > 45%.
^c Downgraded once for imprecision: analysis based on < 400 participants per group.